The thing with pitching and pitchers is that injuries are inevitable. If you ever have time, strongly recommend picking up the book Unhittable by the legend that is Pitching Ninja Rob Friedman. Throughout that book you see the science behind pitching and how one of the goals is to try and prevent injuries and sustain health.
MLB.com
One of the best pitchers in this beautiful sport over the last two years has been Paul Skenes. Got the center of the stage his rookie year and owned it, finishing with the rookie of the year award and being a finalist for the NL CY Young, only to win the award in 2025. Many pegged him to win it this season, but instead it’s been a challenging year for Skenes and the cause for concern really set in after his start Tuesday night against the Miami Marlins.
Was it a bad start? Not exactly no. In fact, it was one of his better starts as of recent. Coming into that start he had given up 13 earned runs in 14.1 innings pitched with two of them being five earned run games. What stands out is in 2025 he had only given up more than three earned runs in a start four times. He’s done that nine times, doubling that total.
The Marlins start wasn’t bad, seeing him pitch five innings, giving up two runs (one earned), one walk, and four strikeouts. Over the course of the start he generated four whiffs, which was and is a season low for him. But that wasn’t the main concern, the concern was the velocity.
When you dive deeper onto Baseball Savant and dig into the start, the immediate standout is the velocity. Across this start, Skenes saw a massive downtick on the four seam fastball (-1.2 MPH). The sinker was also the same exact way and evidently the Pirates pulled him after he had only thrown 65 pitches. That’s not typically normal, especially with the game being so close. Skenes himself touched on being pulled after the game saying, "Not really. If I were the manager I'd probably do it too. ... Wish I could have gone more, but it is what it is."
So this start becomes concerning, but elevates that type of concern that some have had throughout the course of the entire season. Fact of the matter is, the velocity has been the biggest standout of his season and a notable talking point.
Velocity was never a concern through the first two seasons. Skenes was a player that could beat you with his velocity, but also challenged himself by incorporating a two seam pitch for the 2025 season and the goal was finding more ways to beat and attack hitters. The strikeouts are great, but the goal of limiting runs and damage was something that makes him great. Maybe it was also a way to not have to throw as many heaters. This season, he has thrown 95 98+ MPH pitches. For context, he surpassed that total over the first few starts of both the 2024 and 2025 seasons. So, this is completely abnormal for the player.
As you can see by this chart, the velocity had gone down significantly from his 2025 season on the four seam fastball. The same can be said about his sinker too, seeing a 1 MPH downtick in that regard. With the lack of velocity, the swing and miss has changed notably with the sinker, going from 16.7% whiff rate to 8.9%.
That’s one layer of the arsenal that’s taken a back seat. The other element is that his changeup went from being an untouchable weapon, to a pitch that’s gotten knocked around much more. In 2025, the changeup had a run value of nine and this season it’s at -5. The batting average against went from .126 to .247 and the slugging against went from .126 to .397. The contact against the pitch is louder, harder, and doesn’t have the same put away ability it once had. Furthermore, the pitch lost 1.2 inches of horizontal movement.
When you factor in the velocity being down and everything else with the arsenal, that factors into Stuff+ Models. The four seam fastball had a 107 Stuff+ grade (which is well above average), and has dropped to 95. 100 is average. His sinker went from 114 to 97 and his changeup went from 100 to 85. Those are significant drops. The slider is still great and so is the curveball.
There are a lot of great ways that Rob Friedman has helped evolve the game of baseball. The way he dives into pitching, breaks things down mechanically, sees the little things that others don’t is what separates him from a lot of those in baseball. He did a video compilation of Paul Skenes, comparing his throwing mechanics.
In the link shown above, you can see a change in his throwing mechanics. In 2025, the ball was kept right in the glove before the throw, whereas in 2026 the ball was at his hip. That also could play a factor. In fact, he did raise his arm slot 3 degrees, going from 23 to 26.
Skenes is still good this year. The strikeout rate is still 92nd percentile. He is still getting batters to whiff and to chase outside the zone. Also, the Location+ models love him still and the walk rate despite rising is still 78th percentile compared to 87th a season ago. He’s been a poor victim of BABIP, having the tenth highest BABIP in the league (.306). That team really does miss the defense from Konnor Griffin.
Many are simply shocked because he hasn’t been the dominant self we’ve seen across the two seasons, where he consistently has had a 1.96 ERA. Instead, he’s facing adversity and has gone through it this year and it happens to the best pitchers around. After this latest start, it puts an exclamation point on the concerns for Skenes overall this season and the hope is that there isn’t something bigger going on, especially regarding his health.
I destroyed my fantasy team by picking him in the first round. I’m so bad at fantasy baseball!